For a long time, neither the exact function of BioC nor the path to pimelate was understood. Lemoine et al. ([Lemoine96]) proposed that BioC may catalyze the stepwise condensation of malonyl-CoA by addition of acetate units. [ORegan89] cites unpublished results showing lack of growth of a bioC mutant on pimelate, but 13C tracing indicated that pimelate is not a precursor of biotin [Ifuku94]. The function of BioC was finally suggested in a 2010 study [Lin10]. Due to difficulties studying the E. coli enzyme in vitro, the biochemical function of the Bacillus cereus enzyme was determined; expression of this enzyme complements an E. coli bioC mutant [Lin12b].

bioC mutants require biotin for growth [Del67] and appear to be blocked before the synthesis of pimeloyl-CoA [Cleary72]. Monomethyl esters of malonate, glutarate and pimelate allow growth of a bioC deletion mutant in the presence of a heterologous acyl-ACP synthetase that converts these compounds to ACP thioesters [Lin10].